Tuna Gravy & Toast

3 tbsp butter
2-4 tbsp flour
3 cups milk
1 tbsp onion flakes
salt & pepper {to taste}
2 cans tuna, drained
toasted bread

melt butter on low heat in pan
add milk, 2 tbsp flour, onion flakes, salt & pepper {add more flour if needed to thicken gravy}
once thickened, add tuna
cook slowly until onion flakes are clear
tear toasted bread and spoon gravy on top of bread